This application claims priority under 35 U.S.C. xc2xa7xc2xa7119 and/or 365 to SE 9701933-5 filed in Sweden on May 23, 1997; the entire content of which is hereby incorporated by reference.
The present invention relates to a method in a mobile telecommunications system of supporting operator specific services additional to services standardized in the system. In particular the invention relates to a method of supporting additional operator specific services, according to a second telecommunications standard, in a system, which already provides such operator specific services according to a first telecommunications standard.
The invention also relates to an arrangement of functional entities in a mobile telecommunications system through which operator specific services additional to services standardized in the system are supported to a mobile subscriber.
The present invention is based upon the emerging CAMEL standard (Customised Applications for Mobile network Enhanced Logic), which is part of the GSM (Global System for Mobile communication), Phase 2+ standard that is currently being specified by SMG (Special Mobile Group) TC (Technical Committee) of ETSI (European Telecommunications Standards Institute). The main object of CAMEL is to support operator specific services, which are not covered by standardized GSM services to a mobile subscriber, even when the mobile subscriber is roaming outside the HPLMN (Home Public Land Mobile Network), i.e. to specify therefor required inter-network interfaces and underlying networks. The CAMEL feature is not a supplementary service, but a network feature to help the network operator. It is, however, also possible to deploy CAMEL for intra-network usage and to use the part of the CAMEL feature being supported by HLR (Home Location Register), MSC/VLR (Mobile services Switching Centre/Visitor Location Register) and GMSC (Gateway MSC) for invocation of IN (Intelligent Network) based services, which are triggered in a SSF (Service Switching Function) being integrated with the MSC or GMSC, and for routing to stand-alone SSPs (Service Switching Point) and service nodes in the mobile telecommunications system.
Below follows a listing of definitions made in the CAMEL standard, which are relevant to the disclosure of the present invention.
gsmSSF (GSM Service Switching Function)
gsmSSF is a functional entity that interfaces the MSC/GMSC to the gsmSCF. The concept of the gsmSSF is derived from the above mentioned SSF, but uses different triggering mechanisms because of the nature of the mobile network. The gsmSSF of today does not support quite many IN services as the SSF.
gsmSCF (GSM Service Control Function)
gsmSCF is a functional entity that contains the CAMEL service logic to implement OSS (Operator Specific Service), which interfaces with the gsmSSF and the HLR.
gsmSCF Address
gsmSCF Address is an address to be used in order to access the gsmSCF for a particular subscriber. The gsmSCF Address is an E164 number of up to 15 digits.
BCSM (Basic Call State Model)
The BCSM provides a high-level model of GMSC- or MSC/VLR-activities required to establish and maintain communication paths for mobile subscribers. As such, it identifies a set of basic call activities in a GMSC or MSC/VLR and shows how these activities are joined together to process a basic call.
DP (Detection Point)
A DP is a point in processing at which a notification to the service logic can occur and transfer of control to the gsmSCF is possible.
O-BCSM (Originating Basic Call State Model)
The O-BCSM is the originating half of the BCSM and thus the portion of the BCSM, which is associated with the originating party.
T-BCSM (Terminating Basic Call State Model)
T-BCSM is the terminating half of the BCSM. The T-BCSM corresponds to that portion of the BCSM, which is associated with the terminating party.
O-CSI (Originating CAMEL Subscription Information)
The O-CSI identifies a subscriber as having originating CAMEL services.
T-CSI (Terminating CAMEL Subscription Information)
The T-CSI identifies a subscriber as having terminating CAMEL services.
In FIG. 1 is illustrated how a gsmSCF 110 according to a known procedure interacts with a O-BSCM 120, in for instance a MSC, and a T-BSCM 130, in for instance a GMSC, via DPs DP1-DPn; DP12-DPm and gsmSSFs 140; 150. Particular detection points DP2, DPn DP12 and DPm are so called TDPs (Trigger Detection Point), which constitute points in the call progress where triggering of an OSS may occur. A set of TDP data is a collection of such points, that corresponds to a certain set of OSSs. In the present version of the CAMEL standard (CAMEL ph1) is only DP2 used for O-CSI and DP12 for T-CSI. Communication between the gsmSCF 110 and the gsmSSFs 140; 150 is carried out according to a CAP (CAMEL Application Part) protocol, which basically is a sub-set of the INAP (Intelligent Network Application Part) protocol.
PIC (Point in Call)
A PIC identifies a MSC/VLR or GMSC activity, which is associated with one or more basic call/connection states of interest to OSS service logic instances.
Location Information
Location Information indicates the location of a served mobile subscriber. The provision of location information is independent of the mobile station""s status. As part of the location information, is delivered an indication of the age of the information.
Service Key
A Service Key identifies to the gsmSCF a service logic that should apply for a particular mobile subscriber. The Service Key is administered by the HPLMN, and is passed transparently by the VPLMN/IPLMN (Visiting PLMN/Interrogating PLMN) to the gsmSCF in the current PLMN of the subscriber. The Service Key is part of the O/T-CSI.
Subscriber State
Subscriber State indicates the status of the mobile station associated with a certain subscriber. Possible states are: (1) CAMEL Busy, which means that the mobile station is engaged on a transaction for a mobile originated or terminated circuit-switched call, (2) Network Determined Not Reachable, which indicates that the communications network can determine from its internal data that the mobile station is not reachable and (3) Assumed Idle, corresponding to the mobile station being neither CAMEL Busy nor Network Determined Not Reachable.
Default Call Handling
The Default Call Handling indicates whether a call shall be released or continued as requested in case of error in the gsmSSF to gsmSCF dialogue.
Through GSM Technical Specification 03.78, ETSI TC-SMG, March 1997, xe2x80x9cDigital cellular telecommunications system (Phase 2+); Customised Applications for Mobile network Enhanced Logicxe2x80x9d is previously known an architecture for functional entities, HLR, gsmSCF, gsmSSF, GMSC, VLR and MSC, which support the CAMEL feature. The architecture also defines the telecommunications protocols to be used between said functional entities.
In TDoc SMG3 96C324, ETSI STC SMG3-WPC Camel ad-hoc, DeTeMobil, Oct. 21-23, 1996, xe2x80x9cCAP Versionxe2x80x9d is taught a method of deciding which of two possible CAP-versions (CAMEL Application Part) that shall be used for transmission of data between two of the CAMEL specified functional entities, gsmSCF and gsmSSF. The proposed solution implies introduction of a parameter in the data structure containing information for the trigger DPs being defined in the CSI (CAMEL Subscription Information). The parameter may also be used as an indication whether or not a national INAP (Intelligent Network Application Part) should be used instead.
However, if multiple trigger DPs are applied to describe the required support for a specific mobile subscriber""s operator specific services and the CAP versions differ between at least two of the trigger DPs, this procedure will cause an implementation conflict. Besides this, definition of a later CAP version than can be supported in the PLMN in which the mobile subscriber currently is roaming, results in the corresponding services being impossible to support.
The present invention is applicable in a mobile telecommunications system, like GSM. Nevertheless, the invention is not limited to GSM, but may be carried out in any mobile telecommunications system, which supports operator specific services. The invention provides to a mobile subscriber in the system support for a set of operator specific services, additional to the standardized services in the system. The set of operator specific services is accommodated by a structured IN standard, such as CS1 (Capability. Set 1), and offered to the mobile subscriber when roaming in its HPLMN or a VPLMN having equal or better capabilities. Furthermore, the method according to the invention implies that a set of additional operator specific services already is provided for in the system, through a different telecommunications standard, like for instance the CAMEL phi standard.
Expansion of the set of operator specific services according to the method disclosed in TDoc SMG3 96C324, ETSI STC SMG3-WPC Camel ad-hoc, DeTeMobil, Oct. 21-23, 1996, xe2x80x9cCAP Versionxe2x80x9d may cause insoluble protocol conflicts in the communications network. Moreover, inter-working between network equipment from different suppliers is presently impossible to accomplish, since the additional set(s) of operator specific services are not implemented in a standardized manner. An operator will, for instance, therefore be forced to implement and administer different mechanisms for a subscriber, whose services are based on a structured IN standard (like CS1) in the HPLMN and on a OSS standard (such as CAMEL ph1) when roaming.
One purpose of the present invention is thus to provide operator specific services additional to the services standardized in a mobile telecommunications system, whereby no protocol conflicts will occur.
Another purpose of the present invention is to facilitate inter-working between network equipment from different suppliers in a mobile telecommunications system, when better service capabilities are requested than what can be provided by the standardized services in system.
According to a first embodiment of the inventive method information indicating the required support for a first set of operator specific services, which have a functionality provided by a first telecommunications standard, is specified for each subscriber in the mobile telecommunications system. This information is recorded in one or more subscription information fields and stored in a subscriber database. A second set operator specific services, with a functionality provided by a second telecommunications standardxe2x80x94different from the first standardxe2x80x94is also supported to the mobile subscribers, when they are roaming in their HPLMN or a VPLMN having equal or better capabilities. This is accomplished by extending the subscription information field with an intelligent network capability indicator for each subscriber, that requests at least one operator specific service, comprised in the second set of services. The intelligent network capability indicator indicates that a particular intelligent network functionality shall be invoked, which supports the second set of operator specific services.
According to one advantageous embodiment of the inventive method data, defining the intelligent network functionality of the second set of operator specific services, is sent from the subscriber database to the PLMN in which the mobile subscriber currently is roaming. This data is only sent when the subscriber requests one of the operator specific services in the second set. The data is directed to the functional entities that are involved in execution of the particular service. Typically, the data is sent to a GMSC when the subscriber receives a terminating call and to a VLR when the subscriber registers in a particular MSC/VLR.
According to another preferred embodiment of the inventive method, a set of trigger detection point data, which is included in the subscription information field comprises at least one detection point, which supports the second set of operator specific services.
The proposed arrangement of functional entities (such as e.g. HLR, GMSC, VLR, MSC, SCF and SSF) supports a second set of additional operator specific services, with a functionality provided by a second telecommunications standard, to mobile subscribers in a mobile telecommunications system, already providing a first set of operator specific services to its subscribers. The second set of services is available to a certain subscriber at least while being located within the part of the system, which is served by the operator with whom he/she has his/her subscription, i.e. in the HPLMN. Possibly, the second set of services is also available to the subscriber when he/she is roaming in a network, having capabilities equal to or better than the HPLMN, that is served by an operator with which the HPLMN operator has a service agreement. The second set of services is realized by the functional entities and the communications between those entities is carried out in accordance with a structured IN protocol, like the CS1 standard. Likewise can of course any proprietary enhancement of the CS1 standard also be used, as well as subsequent versions of the Capability Set standard (CS2, CS3 etc.).
The present invention offers to a mobile subscriber in the HPLMN-part of any mobile telecommunications system, which supports operator specific services, additional services with a functionality provided by a structured IN.
The structured IN standard in its turn facilitates the inter-working between network equipment from different suppliers in a mobile telecommunications system. Hence, the invention makes it easy to combine network equipment from different suppliers both within a particular PLMN and between different PLMNs.